i have had a few more proba also, so i got to googling. i found CD south africa. who stated;
Could the Cambridge Diet impair vision?
Very rarely, a temporary change in vision shows up if a routine eye test is performed while taking the Cambridge Diet as a Sole Source of nutrition. It can happen when the dieter is not drinking enough while taking the Diet. The lack of fluid in the body causes a loss of fluid from inside the eye, slightly affecting its shape. Drinking more fluid restores the correct shape to the eyeball. It is self-righting once ‘Sole Source’ is finished and does not present a problem.
interesting eh?